High Copper Levels in Used Oil Analysis

High Copper Levels in Used Oil Analysis

High Copper Levels in Used Oil Analysis reasons for concern?

From time to time traces of Copper show up in used oil analysis reports ranging from a few PPM to over a 1000 PPM. Generally, high Copper levels are not a cause for concern unless other wear metals are present in unusual levels.

Copper is a soft metal so it will not promote wear, abrasion, or other damage in equipment. Copper is a component of Bronze and Brass which are used in transmissions, shifters, worm gears, bearings, sleeves, and other areas to help reduce wear. Many crankshaft and camshaft bearings have a bronze layer just below the lead/tin bearing overlay.

Why is copper used in components?

Copper readily transfers heat so it is frequently used in oil coolers and radiators. Some engine oil components can dissolve copper initially in the oil cooler when the engine is new, the oil cooler is new, the oil formulation is changed, the oil is overheated, or the oil change interval is overdue. After the oil cooler has been exposed to the oil a protective film is formed and the copper level will rapidly drop off. If a different oil brand is used, the different formulation may remove the protective film and form a new film thereby providing a spike in the copper level again. If the engine oil is overheated or overdue for a change, corrosive acids may form that will attack the copper and other metals.

There may be other sources for Copper that should be considered. These may include anti-seize compounds, assembly lubricants, gaskets, paint, certain anti-wear compounds, and possibly environmental sources such as dust from mining operations.

Anti-seize and assemble lubricants may take over a 1000 operating hours and more than one oil change to completely remove all the excess materials in a new or rebuilt engine or system.

Possible sources of high Copper levels

Copper is a soft malleable metal that is used in a wide variety of applications. It is non-abrasive and helps prevent wear. The appearance of Copper in a used oil analysis should not be cause for alarm or repair unless other abrasive wear metal such as iron, aluminum, chromium, etc. are present at higher than normal levels. There are several possible sources for high Copper levels. Leaching as mentioned before from oil coolers, leaks from cooling systems, external contaminates, an oil additive, or from excessive wear. In all of these cases, other metals, materials and contaminates will be present.

Remember that each piece of equipment is unique and will have its own typical levels of wear metals and performance, kind of like finger prints. Repairs and replacement should not be determined by one oil analysis, several analyses are needed to determine a baseline and any spikes in wear metals should be checked and investigated.

SWEPCO Lubricants are designed to work in the presence of yellow metals without corrosion or harm.